package com.klxedu.ms.gateway.security.filter;

import java.io.IOException;

import javax.annotation.PostConstruct;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.stereotype.Service;

import com.klxedu.ms.gateway.security.access.CustomAccessDecisionManager;
import com.klxedu.ms.gateway.security.access.CustomInvocationSecurityMetadataSourceService;

/**
 * 
 * Title: CustomSecurityFilter<br>
 * Description: 该过滤器的主要作用就是通过IoC生成securityMetadataSource。<br>
 * securityMetadataSource相当于本包中自定义的MyInvocationSecurityMetadataSourceService。<br>
 * 该{@link CustomInvocationSecurityMetadataSourceService}的作用提从数据库提取权限和资源，装配到HashMap中，
 * 供Spring Security使用，用于权限校验。<br>
 * Copyright @ 2011~2018 Goldgov .All rights reserved.<br>
 * 
 * @author GuoR
 * @createDate 2018年7月17日
 */
@Service
public class CustomSecurityFilter extends AbstractSecurityInterceptor implements Filter {

	@Autowired
	private CustomInvocationSecurityMetadataSourceService mySecurityMetadataSource;
	
	@Autowired
	private CustomAccessDecisionManager myAccessDecisionManager;
	@PostConstruct
	public void init() {
		super.setAccessDecisionManager(myAccessDecisionManager);
	}
	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
		FilterInvocation fi = new FilterInvocation(request, response, chain);
		invoke(fi);
	}

	public void invoke(FilterInvocation fi) throws IOException, ServletException {
		InterceptorStatusToken token = super.beforeInvocation(fi);
		try {
			fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
		} finally {
			super.afterInvocation(token, null);
		}
	}
	

	@Override
	public void init(FilterConfig arg0) throws ServletException {
	}

	@Override
	public void destroy() {
	}

	@Override
	public Class<?> getSecureObjectClass() {
		return FilterInvocation.class;
	}

	@Override
	public SecurityMetadataSource obtainSecurityMetadataSource() {
		return this.mySecurityMetadataSource;
	}

	

}
